java 用接口实现加减乘除计算器

class Test{
    public static void main(String[] args) {
        fun i=new fun();
        jiafa s1=new jiafa();
        jianfa s2=new jianfa();
        chengfa s3=new chengfa();
        chufa s4=new chufa();

        System.out.print("加法结果:");i.func(s1,6,3);
        System.out.print("减法结果:"); i.func(s2,6,3);
        System.out.print("乘法结果:");  i.func(s3,6,3);
        System.out.print("除法结果:"); i.func(s4,6,3);
    }

}
interface Ijisuanqi{
    int jisuan(int a,int b);

}
class fun{
    public void func(Ijisuanqi per,int a,int b){
        System.out.println(per.jisuan(a,b));
    }

}
class jiafa implements  Ijisuanqi{
    public int jisuan(int a,int b){
        return a+b;
    }
}
class jianfa implements Ijisuanqi{
    public int jisuan(int a,int b){
return a-b;
    }
}
class chengfa implements Ijisuanqi{
    public int jisuan(int a,int b){
return a*b;
    }
}
class chufa implements Ijisuanqi{
    public int jisuan(int a, int b) {
        if (b == 0) {

            return -1;
        } else {
            return a / b;
        }
    }
}